Plant Sanitation in Fruit Plantations. F. T. Brooks. 257 



with a larger branch or main stem immediately after removal 

 of the fruit. It is the ugly wounds of broken branches which 

 offer special facilities for the entrance of wound parasites such 

 as Stereum purpureum. 



Where a tree is dying back to such an extent that its loss is 

 inevitable, it is important that the stump should be removed 

 if possible at the time of felling. Unlike the forester, the fruit- 

 grower is little troubled by the action of root parasites, but 

 nevertheless the stumps and the larger roots should be removed 

 in order to prevent the growth of suckers and for the future 

 convenient working of the plantation. If the stump cannot be 

 removed, it should be covered with soil to prevent the develop- 

 ment of dangerous fungi such as Stereum. In the case of plum 

 trees removed on account of silver-leaf disease one has always 

 hitherto hesitated to suggest the planting of other susceptible 

 varieties of plum on the same site, but during the past summer 

 considerable areas ha\'e been seen in which young ' Victoria ' 

 plums have been planted where older silvered trees have been 

 removed; these young trees have remained healthy up to the 

 present, i.e. for a period of 2 or 3 years. Although one is not 

 in a position at present definitely to recommend this course, 

 there seems to be no undue risk in replanting with the same 

 variety, if this is desirable for other reasons, and provided the 

 stumps of the diseased trees are removed. 



As time proceeds, greater care will probably be devoted to 

 the control of such diseases as brown rot of apples and plums 

 which in certain seasons levy a heavy toll on the fruit. In the 

 main, this trouble is carried over from season to season by fruits 

 which, mummified by the action of the fungus, hang upon the 

 trees during the winter or lie on the ground. Where brown rot 

 is liable to be severe, it would be worth while to have these 

 mummified fruits collected and destroyed during the winter. 

 Another closely allied disease, the blossom-wilt which Wormald 

 has shown severely affects ' Lord Derby ' apples, can be dealt with 

 by the excision of the affected spurs. It has been demonstrated 

 that this operation of removing the diseased spurs is com- 

 mercially profitable. Again, the common scab fungus, Fusicla- 

 dium dendriticiim, usually hibernates in the young twigs of the 

 most susceptible varieties of apples, and while pruning is being 

 done, care should be taken that all the twigs which show small 

 pustules in the bark should be cut off. With the common canker 

 caused by Nedria ditissima it is generally recognised that this 

 disease is chiefly dependent upon the nature of the variety and 

 the conditions of the soil. There is evidence too that the in- 

 fluence of the stock is not inconsiderable in this connection. The 

 wise fruit-grower will therefore select his varieties accordingly. 



